<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
<script type="text/javascript">
    var Class = function(){
        var klass = function(){
            alert("1:"+arguments.length);
            this.init.apply(this,arguments);
            alert("1-1:"+arguments.length);
        };
        klass.prototype.init = function(){alert("2:"+arguments.length);};
        return klass;
    };

    var Person = Class();
    Person.prototype.first = function(){alert("4:"+arguments.length);};
    Person.prototype.init = function(){alert("3:"+arguments.length);};

    var person = new Person();

    person.init('aa','bb');
    person.first('aa');
</script>
</body>
</html>